The US Food and Drug Administration (FDA) announced the availability of a revised draft guidance for industry entitled “Product Development Under the Animal Rule” in an early June Federal Register notice.The comments are due by Monday, August 4, 2014. The notice states that “When human efficacy studies are neither ethical nor feasible, US FDA may rely on adequate and well-controlled animal efficacy studies to support approval of a drug or licensure of a biological product under the Animal Rule. This revised draft guidance replaces the 2009 draft guidance for industry entitled “Animal Models—Essential Elements to Address Efficacy Under the Animal Rule” and includes a broader scope of issues for products developed under the Animal Rule. Once finalized, this guidance is intended to help potential sponsors (industry, academia, and government) understand US FDA's expectations for product development under the Animal Rule.” For additional information about this draft guidance and instructions to submitting comments, please refer to the online Federal Register notice.